Bell is married to Bill Bell Jr., the eldest son of Y&R creators William J. Bell and Lee Phillip Bell. They have two children, Liam and Sabrina. Her sister is Marissa Arena who had previously appeared on Y&R as Marissa Barton from 1998-2003.

Bell serves on several nonprofit boards in the arts including P.S. Arts where she serves as president-at-Large [1] and has helped raise funds to provide arts to 11,000 low-income, Los Angeles public school children. Bell chairs the National Arts Awards for Americans For The Arts (a nonprofit advocacy group based in Washington DC), and through the Bell Family Foundation supports the NAA Bell Family Foundation Young Artist Award.[2] At The Museum of Contemporary Art, Los Anageles (MOCA) Bell has served as the Co-Chair of the Board of Trustees since 2009,[3] and has helped raise more than eleven million dollars to support MOCA and its programs. In addition, she sits on the boards of Center Dance Arts, Dicapo Opera Theater, and the American Friends of The Musee Des Arts Decoratifs, Paris. Bell is also a committed and active board member of The Melanoma Research Alliance and Marlborough School, Los Angeles.

In the fall of 2012, Bell was nominated by Mayor Antonio Villaraigosa and subsequently sworn in on December 11, 2012 as Commissioner to the Los Angeles Cultural Affairs Committee.

Before returning to daytime, Bell was an essayist for publications such as "T" the New York Times Style Magazine, "C" Magazine, Aspen Magazine, and Aspen Peak Magazine.

Bell returned to The Young and the Restless in November 2007 and was named Head Writer in March 2008, and co-executive producer in September 2009. She was then elevated to Executive Producer of the series in December 2010.

Bell was credited, along with former co-executive producer Paul Rauch, for rejuvenating The Young and the Restless after former head writer and executive producer Lynn Marie Latham was panned by critics for her detour from traditional storytelling and writing characters to suit her storylines. Bell had many successful storylines, including the return of Marge, Katherine Chancellor's look-a-like, which resulted in the reveal that Katherine Chancellor was not, in fact, Jill Foster Abbott's mother.

On July 25, 2012, a source reported to Daytime Confidential that Bell's co-head Scott Hamner decided to quit Y&R, and this was later confirmed by Soap Opera Digest saying that he would take a leave of absence.[6] "She [Maria Arena Bell] really didn't want me to leave, so I agreed to take a few months off," Hamner said. After the news broke, rumors began to circulate that Jill Farren Phelps was close to being named Y&R's new executive producer.

Two days later, Sony Pictures Television reported via a press release that Phelps has been named executive producer and Josh Griffith, who was previously fired by Sony under Bell's tenure, as head writer.[7][8] Sony thanked Bell for her work and wished her "the best of luck and continued success".[7] Only hours later, Bell posted a statement on her Facebook page about being ousted, sharing that she was "mystified" over being let go by Sony.[8][9] "My ratings are strong... each week stronger than last year. The show is in a great place creatively. We are number one by the greatest margin in the show's history and have been consistently while I've been there. Under no one else's tenure as head writer exec producer have we won every demographic for so long. I am just shy of five years at the helm. It has been an amazing ride. So why am I leaving? There have been a lot of tears shed in the last few days... by me and by my loyal staff and by our iconic actors. I was not given a reason and in fact I have heard nothing from Sony or CBS. They sent me a message through my husband Bill, who had the terrible job of conveying that they'd gone around him and were letting me go," Bell wrote.[8][9] Her statement caused angry words from fans, saying that Bell was in denial.[10] An official reason was not given for Bell's departure,[8] though many insiders have speculated that her departure was prompted by Sony's desire to have more "creative control" over the number one daytime soap opera and the controversial pairing of Sharon and Victor Newman (Sharon Case and Eric Braeden).[8] Phelps and Griffith's first official episode aired on October 12, 2012,[11] however, Bell was still credited onscreen as executive producer until October 22.

The Young and the Restless writing team won the WGA Award for Best Daytime Serial in February 2010 and again in 2013 for work airing under Bell's tenure.[12][13] In 2011, Bell, along with her writing team, won the Daytime Emmy Award for Outstanding Drama Series Writing Team. In December 2012 Bell was honored with the Women's Image Network Humanitarian Award for her contributions to arts and arts education.[14]